The present invention relates to a lighting device for lighting a liquid crystal display (LCD).
A color LCD is used in a portable electronic device such as a portable telephone in recent years. A lighting device for such a color LCD comprises, for example a light source (LED), a lighting panel for applying light from the LED to the color LCD. The light source for the color LCD is required to have high luminance and a low consumption power in order to elongate the life of a battery for the light source.
In a conventional lighting device, a polarization filter is disposed between the lighting device and the LCD in order to absorb unnecessary polarization components. As a result, considerable quantity of light is uselessly absorbed.
Japanese Patent Application Laid Open 11-96819 discloses a lighting device which may satisfy such abhorrent requirements. The lighting device comprises a light source, a lighting panel having an incident surface corresponding to the light source, a lower reflection surface, an upper discharge surface, and a reflection plate disposed below the lighting panel. In the lighting device, there is further provided a polarization dividing plate, a polarized light beam splitter, and others. Thus, the device is complicated in construction because of a large number of parts, which causes the manufacturing cost to increase.